Ultrasonographic cervical length measurement at 10–14 and 20–24 weeks gestation and the risk of preterm delivery

doi:10.1016/j.ejogrb.2006.03.021

European Journal of Obstetrics & Gynecology and Reproductive Biology

Volume 130, Issue 2, February 2007, Pages 176-179

https://doi.org/10.1016/j.ejogrb.2006.03.021 Get rights and content

Abstract

Objective

To compare cervical length measurements at 10–14 and 20–24 weeks gestation in asymptomatic women with singleton pregnancies and to assess the measurements as a predictor of preterm delivery.

Study design

In this prospective study, cervical length was measured in 152 asymptomatic women with singleton pregnancies using transvaginal ultrasonography at 10–14 and 20–24 weeks gestation. The primary outcome measure was spontaneous preterm delivery before 35 weeks of gestation. The mean cervical length was calculated at both stages, and lengths were compared between the term and preterm groups.

Results

The rate of spontaneous preterm deliveries was 10.5%. The mean cervical length at 10–14 and 20–24 weeks was 40.5 and 37.1 mm, respectively. The cervical length at 10–14 weeks was not significantly different between those who delivered at term (40.9 mm) and those who delivered preterm (38.6 mm). By contrast, the cervical length at 20–24 weeks was significantly shorter in the group that had preterm deliveries (28.4 mm) than in those who had term deliveries (37.8 mm) (P < 0.001). The cervical shortening was more apparent in the group that delivered prematurely (from 38.6 to 28.4 mm) than in that which delivered at term (from 40.9 to 37.8 mm).

Conclusion

Cervical length measurement used to predict preterm delivery was found to be more predictive at 20–24 weeks. Cervical length measurement at 10–14 weeks was not reliable for predicting preterm delivery. The mean cervical length tapered gradually from the first to the second scan, and the more rapid cervical shortening was found to be associated with increased risk for preterm delivery.

Introduction

Preterm delivery, defined as delivery before 37 weeks of gestation, is associated with a 15–20% mortality rate and remains responsible for 75% of perinatal deaths in foetuses without anomalies [1]. The accurate diagnosis and prediction of preterm delivery remains a major problem in obstetrics. There is no consensus regarding the evaluation of cervical length during pregnancy for predicting preterm delivery, which may be explained by differences in study populations (low- or high-risk patients), the ratio of primigravidas to multigravidas, the type of investigation (longitudinal or cross-sectional), gestational age at ultrasonographic examination, and racial factors. Several studies consistently found that the shorter the cervical length, the higher the rate of spontaneous preterm delivery [2], [3], [4], [5]. Ultrasonographic assessment of cervical length is becoming an increasingly popular component of prenatal care. However, the role of this method as a screening tool in the prediction of preterm delivery in the first or early second trimester of pregnancy is still controversial [6], [7], [8], [9], [10], [11].

It is important to identify the patients at risk for preterm delivery to avoid unnecessary treatments, such as cerclage, corticosteroids, and antibiotics. Therefore, we investigated whether cervical length in the first trimester (10–14 weeks) predicts spontaneous preterm delivery longitudinally by comparing this measurement with that obtained in the second trimester (20–24 weeks) in an asymptomatic population of singleton pregnancies.

Section snippets

Materials and methods

We conducted this prospective study involving 152 asymptomatic women with singleton pregnancies at our university clinic between February 2003 and November 2004. The ethics committee of our university hospital approved the study and informed consent was obtained from the patients. As part of the routine antenatal care, transabdominal ultrasonography was performed initially, followed by transvaginal ultrasonography to measure cervical length using a real-time 6 MHz curvilinear transvaginal probe

Statistical analysis

A receiver operating characteristic (ROC) curve was constructed for cervical lengths to test the effectiveness of various cutoff points in predicting premature delivery. The areas under the ROC curves were calculated and the sensitivity, specificity, and positive-predictive value (PPV) for the cervical length of the most appropriate cutoff point were calculated for predicting preterm delivery [12]. Cervical length measurements were expressed as the mean ± standard deviation (S.D.). Student's t

Results

One hundred and fifty-two singleton pregnancies met the inclusion criteria during the study period. The mean age (±S.D.) of the preterm and term groups was 27.8 ± 6.9 and 26.0 ± 5.5 years (P = 0.184), respectively. There were no statistically significant differences in previous preterm deliveries, previous miscarriages, education level, parity, or whether the patient was a cigarette smoker between the group that delivered at term and the preterm group. Spontaneous preterm delivery before 35 weeks

Discussion

Unlike most studies that made single measurements, we measured cervical length at 10–14 and at 20–24 weeks gestation in an asymptomatic population of pregnant women. We found an association with the cervical length at 20–24 weeks, which was more predictive, whereas this association was not found at 10–14 weeks gestation. The risk of preterm delivery was higher in pregnant women whose cervical length decreased rapidly from the first to the second scan.

In unselected low-risk asymptomatic

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First-trimester and early-second-trimester transvaginal cervical length before 16 weeks among women with preterm and term birth: a systematic review and meta-analysis
2024, American Journal of Obstetrics and Gynecology MFM
This study aimed to evaluate the differences in first-trimester and early-second-trimester transvaginal cervical length between patients with spontaneous preterm birth and those with term birth.
PubMed, MEDLINE, Embase, and the Cochrane Library were systematically searched through August 2023.
Studies had to include (1) transvaginal cervical length measurement before 16⁺⁰ weeks of gestation and (2) transvaginal cervical length measurement in a population of patients who delivered preterm and at term. Abstracts, studies with duplicated data, and those with cervical length measured by transabdominal ultrasound scan were excluded.
K.W.C. and J.L. searched for, screened, and reviewed the articles independently. The quality of the studies was assessed using the Newcastle–Ottawa scale. Mean differences were calculated using a random-effects model and pooled through a meta-analysis.
A total of 5727 published articles were identified. Only 10 studies (which analyzed 22,151 pregnancies) met the inclusion criteria. All studies excluded iatrogenic preterm birth. Transvaginal cervical length was significantly shorter in women with spontaneous preterm birth than in those who delivered at term (mean difference, −0.97; 95% confidence interval, −1.65 to −0.29; P=.005; I²=69%). When a linear technique was used to measure transvaginal cervical length, a significantly shorter transvaginal cervical length was associated with spontaneous preterm birth as opposed to term birth (mean difference, −1.09; 95% confidence interval, −1.96 to −0.21; P=.02; I²=77%). A shorter transvaginal cervical length measured by other techniques was also associated with spontaneous preterm birth before 34 to 35 weeks (mean difference, −1.87; 95% confidence interval, −3.04 to −0.70; P=.002; I²=0%). When studies where interventions were given for a “short” cervix or studies with a mean transvaginal cervical length ≥40 mm were excluded, a significantly shorter transvaginal cervical length was observed among those with spontaneous preterm birth (mean difference, −1.13; 95% confidence interval, −1.89 to −0.37; P=.004; mean difference, −0.86; 95% confidence interval, −1.67 to −0.04; P=.04; respectively). The optimal transvaginal cervical length cutoff was 38 to 39 mm, yielding pooled sensitivity of 0.80, specificity of 0.45, positive likelihood ratio of 1.16, negative likelihood ratio of 0.33, diagnostic odds ratio of 5.12, and an area under the curve of 0.75.
Women with spontaneous preterm birth had significantly shorter transvaginal cervical length before 16 weeks of gestation compared with those who delivered at term. The linear method and the 2-line method are acceptable techniques for measuring transvaginal cervical length.
No. 257-Ultrasonographic Cervical Length Assessment in Predicting Preterm Birth in Singleton Pregnancies
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N<sup>o</sup> 257-Recours à l'évaluation échographique de la longueur cervicale pour prédire l'accouchement préterme dans le cadre de grossesses monofœtales
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Preventing newborn deaths due to prematurity
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Citation Excerpt :
Transfundal pressure for 15 s is also recommended. The association between ultrasound-estimated cervical length and preterm labour in earlier studies [12–15] was seen only at 20–24 weeks and not at 13–14 weeks. Inability to identify cervical incompetence until 20–24 weeks limits the use of both progesterone and cerclage earlier in gestation.
Preterm births (PTBs), defined as births before 37 weeks of gestation account for the majority of deaths in the newborn period.
Prediction and prevention of PTB is challenging. A history of preterm labour or second trimester losses and accurate measurement of cervical length help to identify women who would benefit from progesterone and cerclage. Fibronectin estimation in the cervicovaginal secretions of a symptomatic woman with an undilated cervix can predict PTB within 10 days of testing.
Antibiotics should be given to women with preterm prelabour rupture of membranes but tocolysis has a limited role in the management of preterm labour. Antenatal corticosteroids to prevent complications in the neonate should be given only when gestational age assessment is accurate PTB is considered imminent, maternal infection and the preterm newborn can receive adequate care. Magnesium sulphate for fetal neuroprotection should be given when delivery is imminent.
After birth, most babies respond to simple interventions essential newborn care, basic care for feeding support, infections and breathing difficulties. Newborns weighing 2000 g or less, benefit from KMC. Babies, who are clinically unstable or cannot be given KMC may be nursed in an incubator or under a radiant warmer. Treatment modalities include oxygen therapy, CPAP, surfactant and assisted ventilation.
Predictive accuracy of changes in transvaginal sonographic cervical length over time for preterm birth: A systematic review and metaanalysis
2015, American Journal of Obstetrics and Gynecology
To determine the accuracy of changes in transvaginal sonographic cervical length over time in predicting preterm birth in women with singleton and twin gestations.
PubMed, Embase, Cinahl, Lilacs, and Medion (all from inception to June 30, 2015), bibliographies, Google scholar, and conference proceedings. Cohort or cross-sectional studies reporting on the predictive accuracy for preterm birth of changes in cervical length over time.
Two reviewers independently selected studies, assessed the risk of bias, and extracted the data. Summary receiver-operating characteristic curves, pooled sensitivities and specificities, and summary likelihood ratios were generated.
Fourteen studies met the inclusion criteria, of which 7 provided data on singleton gestations (3374 women) and 8 on twin gestations (1024 women). Among women with singleton gestations, the shortening of cervical length over time had a low predictive accuracy for preterm birth at <37 and <35 weeks of gestation with pooled sensitivities and specificities, and summary positive and negative likelihood ratios ranging from 49% to 74%, 44% to 85%, 1.3 to 4.1, and 0.3 to 0.7, respectively. In women with twin gestations, the shortening of cervical length over time had a low to moderate predictive accuracy for preterm birth at <34, <32, <30, and <28 weeks of gestation with pooled sensitivities and specificities, and summary positive and negative likelihood ratios ranging from 47% to 73%, 84% to 89%, 3.8 to 5.3, and 0.3 to 0.6, respectively. There were no statistically significant differences between the predictive accuracies for preterm birth of cervical length shortening over time and the single initial and/or final cervical length measurement in 8 of 11 studies that provided data for making these comparisons. In the largest and highest-quality study, a single measurement of cervical length obtained at 24 or 28 weeks of gestation was significantly more predictive of preterm birth than any decrease in cervical length between these gestational ages.
Change in transvaginal sonographic cervical length over time is not a clinically useful test to predict preterm birth in women with singleton or twin gestations. A single cervical length measurement obtained between 18 and 24 weeks of gestation appears to be a better test to predict preterm birth than changes in cervical length over time.
First-trimester screening for preterm delivery
2014, Progresos de Obstetricia y Ginecologia
La realización temprana en el primer trimestre de la gestación de un test de cribado combinado de parto pretérmino y la instauración temprana de estrategias preventivas en los pacientes de alto riesgo pueden disminuir más eficazmente las tasas de parto pretérmino.
En este artículo de revisión, repasamos las distintas variables maternas, gestacionales, marcadores ecográficos, bioquímicos y los modelos predictivos publicados hasta la fecha para el cribado de parto pretérmino en el primer trimestre de la gestación.
First-trimester combined screening for preterm delivery and the early initiation of preventive strategies in high-risk patients can effectively reduce preterm delivery rates.
In this article, we review the maternal and gestational variables, ultrasound markers, biochemical substances, and distinct predictive models published to date for screening of preterm birth in the first trimester.

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Ultrasonographic cervical length measurement at 10–14 and 20–24 weeks gestation and the risk of preterm delivery

Abstract

Objective

Study design

Results

Conclusion

Introduction

Section snippets

Materials and methods

Statistical analysis

Results

Discussion

Preterm birth: a puzzle worth solving

Obstet Gynecol

The length of the cervix and the risk of spontaneous premature delivery

N Engl J Med

Single transvaginal ultrasonographic measurement of cervical length early in the third trimester as a predictor of preterm delivery

Ultrasound Obstet Gynecol

Sonographic measurement of uterine cervix at 18–22 weeks’ gestation and the risk of preterm delivery

Obstet Gynecol

Cervical length at 16–22 weeks’ gestation and risk for preterm delivery

Obstet Gynecol

Cervical changes throughout pregnancy as assessed by transvaginal sonography

Obstet Gynecol

Cervical length at 11–14 weeks’ and 22–24 weeks’ gestation evaluated by transvaginal sonography, and gestational age at delivery

Ultrasound Obstet Gynecol